We investigated 4- and 5-year-olds' (N = 194) appreciation of the link between knowledge and ownership. Namely, we asked whether preschoolers appreciate the ways in which owners are typically knowledgeable about artifacts. Experiment 1 revealed that 4- and 5-year-olds view owners as better sources of knowledge about artifacts than those who simply like artifacts. Experiment 2 built on these findings by showing that 5-year-olds appreciate that owners typically have deep knowledge about artifacts and that they can use this appreciation to guide inferences about who owns what. These experiments are some of the first to investigate how children's inferences about knowledge and ownership are intertwined. As such, they have implications for our understanding of early childhood cognition. First, they provide insights into how object-person relations influence judgments of expertise. Second, they extend current understandings of ownership by demonstrating that ownership influences preschoolers' reasoning in other domains (i.e., knowledge) and by showing that preschoolers' theories of ownership extend beyond normative considerations (i.e., ownership rights). Together, these findings lay the groundwork for a new area of work on how ownership influences children's reasoning about knowledge.